Extrusion mold



ATTRUNZ 2,194,589

EXTRUSYION MOLD mima Aug. 24, 1.957

Patented Mar. 26, 1940 UNITED STATES EXTRUSION MOLD Alionz Kunz, Fuzfo, Hungary Application August 24,

1937, Serial No. l160,646

In Hungary August 28, 1936 8 Claims.

The present invention relates to a device for the preparation of gunpowder in tube form.

The device according to the invention consists of a group of separate replaceable molds in a.

common carrier and independent of one another, each ofwhich consists of a die and a needle independent of the die.

One object of the invention is to provide an extrusion mold unit which comprises a die, a. needle mandrel for said die, and a bridge piece adapted freely to seat upon said die and slidably to receive said needle mandrel, so that said component parts canbe assembled or separated merely by relative movement in a common axial d direction.

Another object of the invention is to provide an extrusion apparatus comprising a common carrier plate for a plurality of multi-part extrusion molds of the kind described in the pre- O ceding paragraph in which each of said plurality of molds is slidably held so that the component parts of said mold are retained in their relative operative positions against force exerted thereon by the extruded material.

The drawing shows one form of construction of the device according to the invention in which Figure 1 shows the carrier in cross-section with out molds. Figure 2 is a plan of the carrier with molds set in. Figure 3 is a longitudinal ure 4 is a plan of the mold according to Figure 3.

In the carriers Il are borings parallel one to the other, the upper parts I2 of which are larger in diameter than the lower parts I3. The upper part of all the borings I2 opens into an annular 'J recess It formed in the upper side of the carrier.

In each boring I2 of greater diameter is inserted a mold according to Fig. 3, which seats itself against the shoulder I5 formed at the junction of the larger bore l2 with the smaller bore I3.

Each die consists of a die part I6 containing the die opening, a bridge Il, a needle I8, and a needle holder I9. In the inner part of the die a is a conical annular space 2l which opens out into the mouthpiece 20, in which space opens the, cylindrical space 22 of the bridge part I1 resting onvthe dies. In the middle part 23 of the part 26 of the bridge Il which contain the needle holder 50 I9 there is also a cylindrical boring. The upper end of the boring 22 open into the boring 24 of the bridge which is conically widened out in an upward direction. The needle holder is also at its lower end 25 corneal and has a handle 2B.

The needle holder is bored longitudinally; in

section of a mold on an enlarged scale and Figthis boring passing the whole length of the holder is the needle I8. The needle is held in the needle holder both above and below and the lower end of the needle holder extends so deeply that only the short end of the needle lying in the die ris not held. As this part of the needle is very short the needle is very rigid against any bending strain from the side.

The boring I3 of the carrier, is appreciably greater in diameter than the opening of the die, so that the tube proceeding out of the die passes on into the boring I3 Without touching the walls thereof.

The device above described is suitable for the preparation of a tube-shaped gunpowder of Il different wall thicknesses or withdifferent inner diameters. With the same outer diameter gunpowder with different thicknesses of walls can be prepared by means of this device simply vby changing the needle fixed in the die. Different outer diameters of the gunpowder can also be made by changing the die.

The borings I2 are so adjusted that they can take different dies. If the needle or the die is damaged only the damaged part requires to be 26 replaced. Now in the device as above described very fine dies and very thin needles maybe used so that this device is applicable in the preparation of tube-shaped molded gunpowders with exceptionally thin walls. Furthermore the prep- 30 aration of tube-shaped molded powder with any desired thickness of wall does not present any diiliculties in the device above described. The needle is accurately held in the needle holder and the precise positioning of the bridge and needle holder ensure a central position for the needle.

I claim:

1. Extrusion apparatus for operation at high pressures for the preparation of tubular bodies of gunpowder, comprising, in combination, a

carrier having a plurality of mold-receiving recesses in its upper surface, each said recess conjoining at its bottom wall with an opening of reduced cross sectional area which opens into the lower surface of said carrier, a plurality of dies slidably positioned in said recesses and resting freely upon the bottom wall thereof without binding engagement between the outer wall of said dies and walls of said recesses, each said die having an opening extending from top to bottom thereof and terminating at its lower extremity in an extrusion opening of reduced diameter, a plurality of tubular bridge pieces slidably positioned in said recess and resting freely upon the tops of said dies'without connection between said 55 rality of shouldered needle holders slidably posi.

tioned in said sleeves, and a plurality of mandrel needles oo-axially mounted in said holders and extending into said die extrusion openings coaxially therewith while the shoulder of each nee-A dle holder rests freely upon the top of its corresponding sleeve and the lower extremity of each said holder extends downwards to act as a support to stiien the operative portion ofk said needle.

2. Extrusion apparatus as claimed in claim 1, wherein each needle holder comprises a handle bored longitudinally thereof to receive a mandrel needle, and having its lower portion shouldered and resting freely upon said sleeve of the corresponding bridge piece without binding engagement between the mutually contacting surfaces of said holder and saidbridge piece, and a needle passed through the .bore of said handle and projecting from the lower extremity thereof to form the needle mandrel lying co-axially in the extrusion opening of the corresponding die. Y

3. Extrusion apparatus as claimed in claim l, wherein each needle holder comprises a handle bored longitudinally thereofA to receive a mandrel needle, and having its lower portion reduced in width and slidably positioned in the sleeve of the corresponding bridge piece without binding engagement between the surface of the reduced portion of said handle and inner wall of said` trusion opening in the corresponding die.

5. Extrusion apparatus as claimed in claim l,v

wherein the said carrier comprises asolid plate having a greater depth than that of said mold.

6. Extrusion apparatus as claimed in claim l,

wherein the cross sectional areas of the openings which lead from said mold-receiving recesses to the bottom of said carrier are greater than the cross sectional areas of the corresponding extrusion openings in saiddies. f

7. Extrusion apparatus for operation at high pressure for the preparation of tubular bodies of gunpowder, comprising, in combination, av carrier plate having a plurality of cylindrical mold-receiving recesses in its upper surface, each said recess terminating intermediate the upper and lower surfaces of said plate and conjoining at its bottom wall with a passage of reduced diameter which opens into said lower plate surface,a plurality of cylindrical diesr slidably positioned in said recesses and resting upon the bottom of said recesses. each said die having a frusto-conical opening therein tapering downwards and conjoined at its lower extremity with a cylindrical extrusion passage which opens into the lower surof said die, a plurality of annular bridge pieces slidably positioned in said mold-receiving recesses and seating upon the tops of said dies, each of said bridge pieces having a central, co-axial sleeve mounted upon radial arms secured to the body of said bridge piece, said sleeve extending downwards and projecting into said frusto-conical opening in said diea. plurality of handled needle holders each bored longitudinally to receive a mandrel needle and having its lower portion reduced to form a shouldered member which is slidably positioned in a corresponding bridge piece sleeve with the shoulder thereof seated upon the top of said sleeve, said reduced portion of said handle extending downwards and projecting into said frusto-conical opening in said die, and a plurality of needles each passing longitudinally through said bores in said handles and projecting from the lower extremities thereof oaxially into the extrusion passages of said dies, said extensions of said sleeves and said handles serving to support said mandrel needles against the lateral thrust of the extruded material.

8. Extrusion apparatus as claimed in claim 7, wherein in each mold the said extensions of said needle holders and said sleeves are bevelled to provide in conjunction with the inner wall of said die al smoothly tapering passage from the upper portion of said die to its extrusion passage.

ALFONZ KUNZ. 

